Various systems exist to deliver volatile compositions, such as perfume compositions, into the air by energized (i.e. electrically/battery powered) atomization. In addition, recent attempts have been made to deliver scents using microfluidic delivery technology, specifically thermal inkjet technology. However, these attempts are generally directed to printing ink-based scented fluids onto a substrate or surface medium using delivery systems and methods similar to those used for printing ink onto a substrate using thermal inkjet cartridges.
Thermal inkjet technology generally employs a replaceable cartridge that contains fluid ink and a micro-electro-mechanical (“MEMS”) based print head that controls the release of the ink from the cartridge. Generally, the print head includes a die having a plurality of fluid chambers, a heater to heat the ink and a nozzle through which the ink is released onto the substrate. Thermal inkjet cartridges are often designed such that the ink disposed therein is delivered to the die by means of capillary forces that transport the ink in the direction of gravity.
However, when the fluid to be released from the cartridge is to be delivered in a direction at least partially against the force of gravity and/or when the fluid is disposed in the cartridge below the nozzle(s), known wicking and/or gravity-feed configurations may not be suitable. For example, it may be undesirable to use a gravity-feed or typical wicking system if the fluid is to be dispensed upwardly because air bubbles can form in and clog the orifices preventing the fluid composition from being released properly through the nozzle. Moreover, depending on the particular configuration of the device, it may not be possible or desirable to use gravity to feed the die, such as, for example, when the fluid is disposed in the device below the nozzle.
Further, typical ink-jet cartridges are generally opaque and do not allow the user to see the amount of fluid left in the cartridge. This can lead to uncertainty as to when refills need to be changed and/or purchased. Further still, many ink-jet cartridges have very little fluid in the cartridge due to internal structures like sponges within the fluid reservoir. These internal structures can also lead to wasted volume in the reservoir and increased costs.
As such, it would be beneficial to provide a microfluidic delivery device that is configured to reduce the likelihood that air bubbles will obstruct the nozzle. Moreover, it would be beneficial to provide a microfluidic delivery device that is configured to ensure the fluid is available to be released even if the device is configured or oriented such that the nozzle is above the fluid to be released. It would also be desirable to provide a microfluidic delivery device having a fluid transport member that is configured to reduce the likelihood of air bubbles entering the fluid path prior to the nozzle(s). It would also be desirable to have a reservoir that enables the user to see the fluid level left in reservoir. Further, it would be desirable to reduce the amount of non-useable volume in the fluid reservoir.